Engine operated burner



z- H. B. HOLTHOUSE ENGINE OPERATED BURNER Filed June 15,1942 2 Sheets-Sheet l Aug; 7, 1945.; B, HOLTHQUSE 2,381,594

* ENGINE OPERATED BURNER Filed June 15, 1942 2 Sheets-Sheet 2 l Trvac YLINDER ENGINE I 1, five/125021 k fiflfffffifiZ/ZiOZZS Patented Aug. 7, 1945 UNITED s'rA'rss PATENT OFFICE ENGINE ornns'mn BURNER Harry BfHolthouse, Chicago, Ill., assi gnor to Galvin Manufacturing Corporation, Chicago, Ill., acorporation of Illinois Application June 15', 1942, Serial No. 447,055

10 Claims. (01. 158-'--.28) I This invention relates generally to pumping devices and in particular to a pump of diaphragm type.

Pumps of diaphragm type are well known in the prior art. These pumps generally have the diaphragm thereof operated by mechanical means. Where a pump of this type is utilized in conjunction with the fuel supply ofian internal combustion engine and is mechanically connected therewith the diaphragm is operated to pump fuel concurrently, with the rotation of the engine. Thus when the engine is being shut an improved pump of diaphragm type which is operable in response to variations in fluid pressures applied on the diaphragm meansthereof.

A further object of this invention is to provide' a diaphragm pump capable of being operated in response to the variable fluid pressures eflected down, fuel will continue to be pumped until the' engine has come to a standstill. In installations where the engine is used as a direct power supply for associated apparatus, such -'as for operating heating apparatus having a burner supplied with fuel by the engine diaphragm pump this con- 7 tinuedpumping action, while the engine is being stopped, is objectionable because of the tendency to flood the burner. v

In the usual assembly of a diaphragm pump in the fuel system of an associated engine, such as an automobile engine, the pump is operated at cam shaft speed. However, on small utility engines, such as fractional horsepower air-cooled type engines, and the like, a cam shaft is not used by the cylinder of a combustion engine during normal engine operation.

Another object of this invention is to provide a diaphragm pump which is of a ru ged and simple construction, light in weight, efllcient in operation, and directly responsive in operation to alternately high andlow fluid pressures applied on the diaphragm means thereof.

A feature of this invention is found in the provision of a diaphragm pump in the fuel supply of 7 an internal combustion engine, whichis responsive in operation to the exhaust impulses discharged from such engine.

Yet another feature of'this invention is found in the provision of a diaphragm pump for supplying fuel to the burner of heating apparatus operated solely by an associated internal combustion engine, in which the pump diaphragm means is arrangedto be acted upon by the fluid through the engine cylinder so as to be so that the diaphragm pump is operated at crank shaft speed. By virtue of the high rotational speed of the crank shaft the follower portion of the pump generally associated with the pump diaphragm and operatively connected with a cam on the crank shaft tends to wear the cam excessively within but a very short period ofoperation.

In these utility engines provision of a gear reduction means between the pump and the crank shaft appreciably increases the initial cost as well as the hull: of the pump-to-engine connecting mechanism so as to practically negative the use of reduction means on engines of this type. As;

a result most utility engines utilize gravity feed fuel systems. Thus on 'a shutting down of the engine, either intentionally or accidentally, fuel continues to flow through the fuel system.

As a result with a fuel system having a me-' chanlcally operated pump or in a system of gravity feed type fuel is accumulated in the combustion portion during engine shut down which interferes with the starting operation of the burner. Further this accumulated fuel at times might cause explosions of a serious nature in the burner when burning is initiated therein.

' It is an object of this invention therefore to provide improved pumping apparatus.

Another object of this invention is to provide vided a diaphragm pump having a casing with i responsive in operation to the variations in the pressures of such fluid to control the fuel feed to the burner.

Further objects, features and advantages of thls-invention will become apparent from the following description when taken in connection with the accompanying drawings in which:

Fig. 1 illustrates the improved diaphragm pump of this invention utilized in the fuel supply of a burner for air heating apparatus operated in conjunction withan internal combustion engine; Fig. 2 is a longitudinal sectional view of the pumping means illustrated in Fig. 1 showing its adaptation for operation in response to the exhaust impulses from an internal combustion ens Fig. 3 is a sectional fragmentary view showing a modifled means iorfluid connecting the pump of Fig. 2 with the exhaust conduit for the engine;

Fig. 4 is' illustrated similarly to Fig. 2 and shows the adaptation of the pump for operation in response to the fluid pressures in the intake line of aninternal combustion'englne; and

combustion engine.

Fig. 5 is a longitudinal sectional view or a modifled form of the invention adapted to be operated either atthe intake or the exhaust of an internal In the practice of this invention there is prodiaphragm means extended thereacross to form expansible pumping and pressure chambers there in, with the diaphragm means constituting a flexible wall portion for each of such chambers. The pumping chamber has an inlet and an outlet each of which has a valve unit therein responsive in operation to the liquid pressures occurring in the pumping and pressure chambers to control the liquid flow through the pump. The pumping action is effected in the usual manner by movement of the diaphragm means to expand and contract the pumping. chamber. This movement of the diaphragm means is accomplished by the fluid connection of the pressure chamber with the exhaust conduit or intake line of an internal combustion engine. The pump may be included as a part of the engine fuel system or operated by the engine to supply liquid'to apparatus associated therewith. The movement of the diaphragm means in response to the exhaust impulses in the engine exhaust conduit, provides for the operation of the pump only when the engine is in actual operation. In other words when the engine is shut down the movement of the diaphragm means and in turn the moving of fuel by the pump is discontinued regardless of whether or not the engine continues to rotate. The pump thus functions to discharge fuel only when actual firing takes place in the engine.

With reference to the drawings the pump ill of this invention is illustrated in Fig. 1 as being included in and common to the fuel supply systems of an internal combustion engine II and a burner or combustion chamber I2 of an air heating apparatus pperated by the engine. The engine it includes an air cooled cylinder iii, an exhaust conduit i 4 for the cylinder !3, and a shaft is for carrying a fan H which supplies combustion air and air to be heated to the heater apparatus. The engine H, the scroll or housing l8 for the fan it, and a fuel tank i for the engine If and combustion chamber I2 are supported on top of the combustion chamber and in alignment longitudinally thereof. I

The combustion chamber l2, which is shown in development in Fig. 1 for the purpose of clarity,

is of a substantially cylindrical shape and divided into four axially extended but connected passages 490-4911 by partition means 2|. The combustion chamber 02 is closed at one-end by a cover passage 28 is co-extensive in length with the combustion chamber I2 and the member 24 and is separated from an air supply chamber 29 by a partition member 8! positioned about the member 24 and arranged transversely of the heater housing 21. The air supply chamber 28 is seen from ,Fig. 1 to be in longitudinal alignment with the combustion chamber l2 and defined by the member 24. partition plate 8| and the end 32 of the heater housing 21.

' Air to be heated enters an inlet 88 in the fan housing l8 and is discharged into the passage 28 for circulation about the combustion chamber l2 and outwardly from the heater through an outlet 84. The air for combustion delivered to the air supply chamber 29 is also provided by the fan I1 through an inlet opening 88 formed in the peripheral rim of the cup-shaped member 24. In other words the air from the fan ll enters the passage 28, with a portion of such air being by-passed The air for combustion is mixed with the fuel I supplied by the pump H! in a fuel conditioning means, indicated generally as 81, which includes a tubular casing 38 having a substantially closed end portion 38 extending into the air supply chamber 29, and an opposite end 4| which is open and in fluid communication with the combustion passage l9a of the combustion chamber 12. An air and fuel mixing chamber 42 is located at the closed end of the casing 38 and is separated from an equalizing chamber 43 by a plate member 44 having perforations 48 therein. The equalizing chamber 43 in turn is both defined and separated from the combustion chamberpassage 19a by a perforated heat insulating plate .41. Extended substantially axially through the casing 38 is the end portion 48 of the engine exhaust conduit l4. The casing 38 and partition plate 44 are provided in a heat conducting material and are in thermal connection with the conduit end portion 48 so as to readily receive heat from the exhaust gases passing therethrough. The heat thus radiated from the exhaust conduit portion 48 is adapted to heat the air and fuel mixing means 31 to at least a fuel vaporizing temperature to facilitate the mixing together of the fuel and air admitted therein, with such vaporous mixture being ignited by an igniter element 49 located in the passage l9a adjacent the end 4| of the casing 38. The igniter 49 is connected in the ignition circuit for the engine, which includes a spark plug 50 and a magneto (not shown).

A fuel nozzle or delivery means 5| carried at the casing end 39 and located within the air supply chamber 29 is connected with the outlet 52 of the pump I0 through a pipe 58. A

' portion of the air for mixing with the fuel enters the nozzle 5| through ports 64 and travels with this fuel into the mixing chamber 42. Further air is admitted directly into the mixing chamber 42 through apertures in the casing 38 arranged about the fuel nozzle 5!. The fuel thus entering the mixing chamber 42 is heated to at least a fuel vaporizing temperature by the heat from the exhaust conduit end portion 44 for intimate mixing with the air in such chamber. This vaporous mixture passes into the equalizing chamber 43 through the apertures 44 in the partition plate 44. The equalizing chamber acts to reduce the turbulence in the mixture, as eifected by the air flow in the chamber 42, and to disperse the mixture substantially uniformly across the entire cross section *of the casing 88 that a mixture of substantially uniform fuel characteristics passes through the perforated heat insulating plate 41 and into the combustion passage l8a where it is' ignited by the spark means 48 and mixed with the engine exhaust gases from the conduit l4 for burning therewith. The admission of the air and fuel to the fuel conditioning means 31 thus controls directly the operation of the combustion chamber l2. The exhaust gas from the combustion chamber I2 is discharged therefrom through an exhaust assembly an in' fluid communication with the combustion passage i941 and extended through thehousing end 82.

-the proper starting of the heater.

In the operation of the heater it is desirable that the operation of the pump follow closely the operation of the engine. previously mentioned in connection with the prior art, the usual type diaphragm pump which is mechanically connected with an engine such as H continues to pump fuel so long as the engine rotates. It is apparent, therefore, that when the engine H is shut down fuel will be supplied to the conditioning means 31 during the, time interval between the shutting down of the engine and its coming to an actual stop. This fuel accumulates in the conditioning means or in the combustion chamber 12 so as to flood the same. As a result an excess of fuel is present in'either the conditioning means 31 or the combustion chamber l2 so as tointerfere with Further the vapors resulting from the accumulated fuel might result in a combustible mixture being present in the combustion chamber l2, prior to a flow of air therethrough sufflcient to move the vapors through the combustion chamber, which effects an initial explosion of objectionable proportions. These difilculties are entirely eliminated by the diaphragm pump of this invention one form of which is shown in Fig. 2.

With reference to Fig. 2 the pump I is seen to include a housing comprised of casing portions 56 and 51 having flange portions 58 and 53, respectively, adaptedfor mating engagement and secured together by screws or the like 6|. A pumping chamber 62 and a pressure chamber 63 are formed within .the pump housing by a diaphragm 64 extended transversely of the pump housing with the marginal edge thereof retained between the flange portions 56 and 59. The diaphragm 64 is composed of a usual resilient material to provide for its deflection in an up and down direction as viewed in Fig. 2. It is seen, therefore, that the diaphragm 64 forms a common flexible wall for the chambers 62 and 62 to provide for the expansion and contraction of such chambers. The pumping chamber 62 has an inlet 66 and an outlet 52 each of which is provided with a valve unit 61 and 65, respectively, including-,a'disc 66 normally retained on a corresponding seat portion by a spring H, the discs 66 being opened in response to the liquid pressures acting thereon to permit'a flow of liquid in one direction. On an increase in pressure in the pressure chamber 63 the diaphragm 64v is moved or deflected upwardly as viewed in Fig. 2 whereby to contract the pumping chamber 62 and increase the pressure on the liquid therein. This increase in pressure lifts the disc 66 in the valve unit 65 to permit fuel .being discharged through the outlet 52. On a release or decrease of thepressure in the chamber 63 the diaphragm .64 is moved downwardly as viewed in Fig. 2 by the action of a spring 12 arranged in compression within the liquid or pumping'chamber 62. This action of the spring 12 expands the chamber 62 to decrease the pressure therein, whereby the disc 66 in the valve unit I! is. lifted away from itscorresponding seat against the pressure of a corresponding I spring H to permit the drawing or passage of fuel into the pumping chamber 62 through the inlet 66, which is connected by pipe 16 to the fuel tank ii. on an increase of pressure in the pressure chamber 63 this fuel is discharged through the outlet 52 as above explained.

The increase and decrease of pressure in the pressure chamber 63 is accomplished in the pres- Thus as was 3 eat invention by fluid connecting the pressure chamber 63 with the exhaust conduit l4 of the engine H. In the operation of an internal combustion engine it is well known that the exhaust impulses or discharges therefrom are emitted in succession so as to create or efiect a pressure wave in the engine exhaust conduit. In other words each exhaust impulse may be considered as having a mass, which passes through the exhaust conduit at a certain velocity. As this mass progresses through the exhaust conduit it gases through the exhaust conduit l4 at the connection 15, between the pressure chamber 63 and exhaust conduit l4, effects alternate high and low pressures at the connection 15 and in turn in the pressure chamber 63. Thus when an exhaust impulse or mass of exhaust gases is passing through the exhaust conduit the pressure in the pressure chamber 63 is alternately increased and decreased. When the pressure in the chamber 63 is increased the diaphragm 64 is moved upwardly, as viewed in Fig. 2, against the pressure of the spring 12. This movement of the diaphragm constitutes the working stroke for the pump and serves to discharge fuel through the outlet 52. On passage of the exhaust impulse beyond the connection 15 the pressure -in the chamber 63, is decreased so as to permit the movement of the diaphragm 64 downwardly, as also viewed in Fig. 2, in response, to the action of the spring I2. This movement or the diaphragm 64 provides the suction stroke for the pump [6. In some instances the spring 72 may be eliminated by virtue of the fact that the pressure decrease following the passage of the mass of exhaust gases beyondthe connection I5 is suilicient to pull the diaphragm 64 downwardly.

It is unnecessary that the diaphragm 64 be of any particular heat resistant material since the exhaust gases in the pressure chamber 63 are not continuously admitted thereto and withdrawn therefrom. In other words the intialvexhaust gas admitted into the pressure chamber 63 is substantially retained therein during subsequent operation of the pump I II, and acts as a column or quantity of gas which is acted upon by the exhaust gases normally passing through the exhaust conduit 14; Since this quantity of initial gas becomes cooled by its retention in the chamber 63 and connection 15 it acts as a heat insulator relative to the diaphragm 64 and protects the same from the heat of the exhaust gases nornection 15 within the exhaust conduit I4 is generally not critical, so that the connectioncan terminate substantially within the periphery of the conduit l4 or may extend therein. However, where the pressure as effected by an exhaust discharge is relativelylow the connection 15 may be formed, as indicated in Fig. 3 for the connecsure in the exhaust conduit resulting from the passage of the exhaust impulses therethrough is effected as a result of a back pressure in the exhaust conduit. It is desirable, therefore, that the connection .15 or [6 for the pump Ill be located on a portion of the exhaust conduit I4 capable of having a back pressure produced therein.

As above described it is seen that a working stroke of the diaphragm 66 is accomplished in response to the action thereon resulting from an exhaust impulse or discharge passing through the exhaust conduit it. The pump it therefore, is operative only when exhaust gases are passing through the conduit it and is rendered inoperative on stopping or cessation of such exhaust flow. Thus on shutting down of the motor Ii, and specifically the cutting ofl of the ignition thereof, active combustion therein is stopped so that only residual exhaust gases are emitted from the exhaust conduit iii. tend to flow through the exhaust conduit ll at a substantially constant pressure which is far below the pressure created therein by the high velocity flow of exhaust gases during normal engine operation. On shutting off the engine ignition, therefore, the pump III is rendered inoperative so that fuel to the fuel conditioning means 31 is stopped substantially concurrently with the cutting oil of the engine ignition. Since air from ditioning means 31 and combustion chamber I! of any residual fuel. Thus on later starting of the heater apparatus the combustion chamber [2 is free of any accumulated or residual fuel vapors so that combustion is initiated efliciently and smoothly and without danger of explosion. Since the pump I is responsive in operation to the occurrence of an actual firin of the engine II it is rendered inoperative during any protracted or prolonged period of misflring by the engine. In other words when the engine fails to operate normally and misses fire frequently before coming to an accidental shutdown, the pump ID will operate to automatically stop the supply of fuel through the fuel system during the periodof misfiring. The fuel supply is thus closed by the time the engine comes to a standstill.

Although the pump of Fig. 2 has been described above relative to its operation with the exhaust conduit II, it may also be operated at the intake to the engine cylinder ll. When the pump is to beoperated at the engine intake the spring 12 is arranged within the pressure chamber -63, as is illustrated in Fig. 4. On the suction stroke of the engine piston a suction pressure is effected in the intake line H and pressure cham- These residual gases ber 63 which acts to draw the diaphragm 64 12 thus actuates the diaphragm 64 to eflect a working stroke thereof, with the suction stroke of the diaphragm being accomplished by the suction intake pressure in the engine intake l4.

A modified form of the invention is illustrated in Fig. 5 in conjunction with an internal combustion engine I la having at least two cylinders "a and lib, with corresponding exhaust conduits 16 and H extending from the exhaust openings 16a and Ila thereof. The pump ID has a housing comprised'of four casing sections including two corresponding end sections 18 and II and corresponding intermediate sections I! and 78'. A working or pumping diaphragm II is extended across the pump housing with the marginal edges thereof retained between the end casing 18 and the intermediate casing ll, while an actuating diaphragm 82 is positioned across the pump housing with the marginal edges thereof held between the end section 18' and the intermediate section- 19'. A thir or idlin diaphragm It has the marginal edges thereof secured between the inner sections 18 and I8, all three of the diaphragms 8|, B2 and 88 being connected for movement together by a connecting pin or rod 84. The diaphragm 8| forms a flexible wall for a pumping chamber-62' located within the end section 18. Two pressure chambers are utilized in this embodiment of the invention, one pressure chamber 88 being formed between the diaphragms 82 and II in the intermediate section I! and the second pressure chamber 81 being formed by the diaphragm 82 within the end housing section II. The chamber." formed betweenthe diaphragms 8| and 83 provides no function in the operation of the pump and is formed with a bleeder opening '0 to prevent any build up of pressure therein. The pressure chamber 88 is fluid "connected through a connection 88 with the exhaust cona tube IS. The passage of an exhaust impulse. from a corresponding cylinder associated with the exhaust pipes 16 and 11 produces a pressure wave therein as was fully explained above in connection with Fig. 2.

with the engine cylinders I la and lib adapted to be fired in succession the pressure in the chambers l6 and I1 varies alternately. In other words when the pressure in the chamber 88 is at a maximum value the pressure in the chamber 81 is at a minimum value and conversely a high pressure in' the chamber .1 occurs when'a low pressure exists in the chamber II. The alternate occurrence of these high pressures on opposite sides of the diaphragm 8! acts to move the same in opposite directions to in turn actuate the working diaphragm ll, the reversed movement of the diaphragm ll providing for a movement of the fuel by the pump II in a manner which is similar in all respects to that described for the diaphragm N in Fig. 2. By virtue of the connecting member being common to all three of the diaphragms II, II and I! it is readily apparent that any increase in pressure in the chamber It acts against both of the diaphragm l2 and 8! tending to move the same in opposite directions. However, by virtue of the large area of the dia:

phragm 82 relative to the diaphragm II the diaphragm II is moved in the direction of movement of the diaphragm 82.

In the operation of the pump Ill from the engine intake rather than from the engine exhaust the structure thereof remains unchanged and intake lines are substituted for the exhaust lines 10 and 11. Since the pump 10' is'operated entirely by high and low pressures acting alternately on opposite sides of the diaphragm 82 these pressures will occur in the chambers 86 v As shown in Fig. 1 the pump in is illustrated a as being common to the'fuel supply systems for both the engine II and combustion portion l2, the engine fuel system including a supply line 95 connected to the pump feed line 53, and having therein a sediment bowl SI and a carburetor 92. Since the pump H} is inoperative until flring actually occurs in the engine I I it is apparent that no fuel is supplied to the feed line 53 until after the engine is in operation. This operation of the pump, however, does not interfere with the starting of the engine because of the reserve fuel initially present in the sediment bowl 9| and carburetor 92, It is apparent, therefore, that the pump of this'invention is entirely adapted to operate, satisfactorily in the fuel system of an internal combustion engine. In one embodiment of the invention operated in conjunction with a single cylinder four cycle engine rated at horse power, a capacity of five gallons per hourwas accomplished when. using a three sixteenth inch tube at the outlet 52. In this embodiment of the invention the working diaphragm-had a maximum amplitude of three sixteenths inch. With the tube or line 53 at the outlet 52 of a somewhat means connecting the same for movement together, said casing having a pumping portion therein with one of saiddiaphragm means constituting a flexible wall for said pumping-portion, and a fluid portion with another of said diaphragm means extended thereacross, and 'means connecting saidcylinder fluid passages with said fluid portion at different sides of said last-named diaphragm means.

2. In combination with an internal combustion engine having two alternately operated cylinders each provided with a corresponding opening for carrying exhaust gases therefrom, a liquid pump including .a casing, a pair of diaphragm means in said casing separated from each other but connected for movement together, means connecting said exhaust openings respectively to different sides of one of saiddiaphragm means, whereby the exhaust discharge through said ex haust penings act on said' one diaphragm meansto reversely move the same, and a pumping chamber in said casing having a wall portion formed by the other of said diaphragm means to expand and contract the same.

3. In combination with an internal combustion engine which includes at least one cylinder and is provided with an exhaust opening, heating apparatus including means defining a combustion chamber, air moving means driven by said engine to supply air to said'combustion chamher, a fuel pump actuated by the exhaust gases restricted construction, for example having an inner diameter of .050 inch, a constant pressure of one pound per square inch was maintained in the line 53 witlva delivery or capacity of one and one-half gallons per hour. It is seen, therefore, that the discharge of the pump is sufliciently ample for normal engineoperation and capable of operating against appreciable line pressures.

From a consideration of the above description and drawings, therefore, it is seen that the invention provides an improved diaphragm pump which is capable of being operated entirely in re,- sponse to alternate high and low, pressures acting on the diaphragm means therefor. As a result the bulk and weight of the pump is appreciably reduced, and when used in connection with an internal combustion engine all of the actuating mechanism usually required for driving or operating the pump is entirely eliminated. The pump is simple in design and rugged in construction and capable of producing relatively i high operating pressures. It is obvious of course that the pump is not restricted in operation to the intake and exhaust of an internal combustion engine, but can be operated by any means capable of producing alternate high and low, fluid pressures.

Although the invention has been described specifically with reference to several preferred embodiments thereof it is to be understood that it is not so limited since modifications and alterations can be made therein which 'are within the full intended scope of this invention as defined by the app nded'claims.

I claim:

1. In combination with an internal combustion engine having a pair of alternately operated cylinders and a fluid passage individual to and in fluid connection with each cylinder, .with the fluid in said passages creating alternate high and low pressures therein, a liquid pump including a casing having a plurality of diaphragm means therein, means common to said diaphragm transmitted through said exhaust opening from said cylinder during operation of said engine, and means including said fuel pump for delivering fuel to said combustion chamber only when fuel combustion occurs in said engine. I

. 4. In combination with an internal combustion engine which includes a cylinder'and an exhaust conduit, heating apparatus including means defining a combustion chamber, air moving means driven by said engine to deliver combustion air to said combustion chamber, a fuel pump actuated directly in response to pressure fluctuations which are roduced in the exhaust gases traversing said conduit by the intermittent combustion of fuel within said cylinder, and means includin a said fuel pump for delivering fuel to said combustion chamber only when fuel combustion occurs in said engine.

5. In combination with an internal combustion engine which includes at least one cylinder and is provided with an exhaust opening, heating apparatus including means defining a combustion chamber, air moving means driven by said engine to supply air to said combustion chamber, a fuel pump actuated by the exhaust gases transmitted through said exhaust opening from said cylinder during operation of said engine, means including said'fuel pump for delivering fuel to said combustion chamber only when fuel combustionoccurs in said engine, and means for utilizing the heat energy of saidexhaust gases to preheat the fuel before it is delivered to said c'ombustion chamber.

6. In combination with an internal combustion engine which includes at least one cylinder and-isprovided with an exhaust opening, heating apparatus including means defining a combustion chamber, air moving means driven by' said engine to supply. air to said combustion chamber, a fuel pump actuated by the exhaust I fuel combustion occurs in said engine and means including said pump for also delivering fuel to said engine.

7. In combination with an internal combustion engine which includes moving parts, heating apparatus including means defining a combustion chamber, air moving means driven by said engine to deliver combustion air to said combustion chamber, a fuel control device actuated by said engine only when fuel combustion is occurring in said engine and regardless of whether said moving parts are at rest or are moving; and

means including said device for delivering fuel I to said combustion chamber only when said device is operating.

8.111 combination with internal combustion heating app ratus including means defining a combustion chamber, means for producing a heated fluid and for discharging said fluid with fluctuations in the discharge pressure thereof,

energy from said gases to the fuel prior to admission of the fuel into said combustion chamber and for then discharging the heated gases into said combustion chamber.

10. In'combination with means defining two fluid passages adapted to have alternate high and low fluid pressures developed therein at related intervals such that each period of high pressure in either passage corresponds to a period of low pressure in the other passage, 9, fluid pump including a casing, three diaphragms in said casing, means connecting said diaphragms together for concurrent movement, the first of said diaphragms defining a pumping chamber within said casing, the second and third diaphragms dividing a portion of the space within said casing into two actuating chambersv which are respectively disposed on opposite sides of said third diaphragm, and the first and second diaphragm defining a fourth chamber within said casing, said casing being provided with a breather passage communicating with said fourth chamber, and means respectively and individually connecting said fluid passages with said actuating chambers.

HARRY B. HOLIHOUSE. 

